Influence of Long-Term Use of American Football Helmets on Concussion Risk.

In this study, to discuss the influence of concussion risk from the long-term use of American football helmets on collegiate teams, accident cases during the game are replicated based on game videos by simulations using whole-body numerical models and helmeted finite element human head models. The concussion risks caused by collisions were estimated using the mechanical parameters inside the skull obtained from finite element analyses. In the analyses, the different material properties of helmets identified by free-fall experiments using headform impactor-embedded helmets were used to represent brand-new and long-term-use helmets. After analyzing the five cases, it was observed that wearing a new helmet instead of a long-term-use one resulted in a reduction in the risk of concussion by 1 to 44%. More energy is attenuated by the deformation of the liners of the brand-new helmet, so the energy transferred to the head is smaller than that when wearing the long-term-use helmet. Thus, the long-term use of the helmet reduces its ability to protect the head.

Evaluating distribution and variation of strains near eyes in blinking using digital image correlation.

BACKGROUND: Strain is occurred due to deformation such as the change of facial expression and is expected as a new evaluation approach to know the condition of skins applied to cosmetics. In this study, a noncontact in-site method by using digital image correlation for measuring the strain on the skin surface near the eyes where deformation always occurs by blinking is proposed. In this method, skin microrelief and irregularities are utilized for the measurement. MATERIALS AND METHODS: Images on the skin surface below the eyes of the four female subjects are pictured during a blink using high-speed cameras. The principal strains as well as the principal directions are obtained using digital image correlation. The reference updating algorism is used when the movement of the skin surface due to blink is large, and the eyelashes elimination algorism is used when the long eyelashes hide their skin surface in an image. The strain distributions in the local area below the right eye and the time histories of the strain near the eye under several skin conditions are evaluated for each subject. RESULTS: The strain can be obtained for each subject under each condition and the different strain distributions and time histories under different condition are visualized. CONCLUSION: The individual behavior of the subject and the different condition of the skin can be captured by the proposed method.

Evaluation and visualization of facial massage effects by using ultraviolet stereo-image correlation.

BACKGROUND/PURPOSE: This study proposes a technique for visualizing the effect of facial massage using stereo-image correlation with melanin pigment. METHOD: In this method, the melanin pigment of a subject's face is made visible by using an ultraviolet light and utilized as a random pattern for stereo-image correlation. Stereo-pair images of the face with the melanin pigment before and after facial massage are recorded using a desk-sized measurement equipment. Then, the deformation of the face by the massage can be obtained based on the principle of stereovision. The effectiveness of the proposed method is demonstrated by applying it to the massage effect evaluation of eight subjects (females in their 40s). RESULTS: The results show that the massage effect can be visualized from the displacement and strain distributions across the face obtained by the proposed method. In addition, it is observed that the face is displaced significantly by the massage and individual differences between the subjects can be captured. CONCLUSION: The proposed method is effective for evaluating the effect of a facial massage when the painted pattern disappears due to the applied cream during the massage.

Rescue percutaneous thrombectomy system provides better angiographic coronary flow and does not increase the in-hospital cost in patients with acute myocardial infarction.

In acute myocardial infarction (AMI), slow flow (

Oxidized low-density lipoprotein and high-density lipoprotein cholesterol modulate coronary arterial remodeling: an intravascular ultrasound study.

BACKGROUND: Oxidized low-density lipoprotein (oxLDL) not only plays an important role in plaque formation, but also impairs the endothelium-dependent relaxation. Constrictive remodeling rather than intimal hyperplasia mainly contributes to restenosis after balloon angioplasty. Probucol (powerful antioxidant) reduced restenosis rate by improving constrictive remodeling. Thus, oxLDL may modulate coronary arterial remodeling. HYPOTHESIS: The study was designed for using intravascular ultrasound to test the hypothesis that arterial constrictive remodeling (CR) was associated with oxLDL in patients with coronary artery disease. METHODS: Intravascular ultrasound was performed in 36 patients with de novo atherosclerotic coronary. Remodeling was defined and evaluated as follows: remodeling index (RI) = lesion vessel area (VA)/(proximal reference VA + distal reference VA)/2. Constrictive remodeling (CR) was defined as remodeling index (RI) < 0.9. Neutral and expansive remodeling (NER) was defined as RI > or = 0.9. The level of plasma ox-LDL was measured by sandwich ELISA using the monoclonal antibody (DLH3)-recognized oxidatively modified lipoproteins and the antihuman apoprotein B monoclonal antibody. RESULTS: Neutral and expansive remodeling was found in 24 lesions, and CR in 12 lesions. Remodeling index was significantly lower in the CR group than in the NER group (0.8 +/- 0.1 vs. 1.0 +/- 0.1, p < 0.001). The level of oxLDL in the CR group was significantly higher than that in the NER group (24.0 +/- 12.1 vs. 16.4 +/- 6.2 U/ml, p < 0.05). The level of high-density lipoprotein-cholesterol (HDL-C) in the CR group was significantly lower than that in the NER group (40.5 +/- 4.8 vs. 46.2 +/- 10.6 mg/ml, p < 0.05). There was a statistically significant correlation between the value of HDL-C/ ox-LDL and the RI (r = -0.48, p < 0.005). CONCLUSIONS: Oxidized LDL and HDL-C were associated with arterial remodeling in de novo atherosclerotic lesions.

Sonodynamic therapy decreased neointimal hyperplasia after stenting in the rabbit iliac artery.

BACKGROUND: In-stent restenosis remains a pivotal problem after coronary and peripheral stenting. Sonodynamic therapy inhibits tumor growth by means of cytotoxicity after the activation of sonochemical sensitizers by ultrasound. PAD-S31 is known to be a water-soluble, chlorin-derivative sonochemical sensitizer. We assessed the efficacy of sonodynamic therapy using this sensitizer on neointimal hyperplasia in a rabbit stent model. METHODS AND RESULTS: Stents were implanted in the iliac arteries of 16 rabbits. A total of 32 stented arteries were randomized to sonodynamic therapy, control, ultrasound exposure, and PAD-S31 groups. One hour after the intravenous administration of PAD-S31 (25 mg/kg body weight), ultrasound energy (1 MHz, 0.3 W/cm(2)) was delivered transdermally to the sonodynamic therapy group. At 28 days, all stent sites were analyzed morphometrically. The size of the intimal cross-sectional area was smaller in the sonodynamic therapy group than in the control, ultrasound, and PAD-S31 groups (0.31+/-0.07 versus 1.38+/-0.47, 1.66+/-0.71, and 1.61+/-0.42 mm(2), respectively; P<0.05). The ratio of the intimal and medial cross-sectional area was smaller in the sonodynamic therapy group than in the control, ultrasound, and PAD-S31 groups (0.71+/-0.22 versus 2.53+/-1.39, 2.48+/-0.60, and 3.45+/-1.42 mm(2); P<0.05). CONCLUSIONS: Sonodynamic therapy with PAD-S31 is considered to be a feasible treatment modality for noninvasively inhibiting neointimal hyperplasia in a rabbit iliac stent model.